Camera trigger using Pixfalcon

Is it possible to use the “Trigger camera at set distance intervals” in Qgroundcontrol on Pixfalcon hardware? Trouble is, that Pixfalcon only have the 8 main outputs, not any Aux outputs. I fly a flying wing, so I do have spare main outputs, but I don´t know how to enable them for use as camera triggers. I found lots of bits and pieces of information and solutions during endless googeling, but nothing that led me to a solution. I tried to make a mixer but did not have any succes, not too surprising, as I have no knowledge of programming.
I have spent an awful lot of time getting my Z-84 to fly using Qgroundcontrol and PX4. I am very content with the results and the only thing I am missing now is the distance based shutter control. So any help would be highly appreciated.


What are you trying to change about the mixing?


Lorenz Meier himself! Thank you very much for answering my post.
It’s simple, really: What I want is to use the camera-feature in Qgroundcontrol, i.e. to make the autopilot trigger my camera at at for example every 40 meters. My autopilot is a Pixfalcon (only 8 main outputs, no aux. 3 main outputs are used for elevons and throttle o my flying wing, which leaves 5 unused) My camera (Gitup Git 2) can be triggered by PWM signals.
So I really just need to tell the autopilot to send the PWMsignal for the camera to one of the 5 free main outputs and connect the camera to that pin. Question is: How do I tell the autopilot which of the unused pins to send the signal to. I was under the impression, that I needed a mixer to do that. But of course, if there is a simpler way, I would much prefer that.
Best regards

Hi Jakob,

Sorry for the delay, I was travelling. The camera trigger is currently only designed for the AUX outputs (which the Pixfalcon is lacking). It would be actually feasible to run it on the MAIN outputs as well, but you’re the first person trying to do that. If there is more interest we might find someone to pick this up. Otherwise using a Pixracer might be a good alternative, as everything works out of the box there already and we have direct support for the Seagull MAP2 cable (including power control for the camera).

Thanks, Lorenz. I think I have seen quite a few looking for cameracontrol without AUX outputs, but of course I understand that the ressouces should be used where most users can benefit. Keep up the good work.

Add me as someone else looking to do this. Remapping the AUX1 and AUX2 to a spare PWM output on the Pixfalcon would be very useful. I have 8 “motor” outputs but only need 4, that leaves another 4 I could be using for aux servo’s (e.g. landing gear) and/or gimbals. I’m setting up the dev environment to see how this works now.

@LorenzMeier - Would be great if you could write code to a re-map and drive PWM Aux1->4 over to the unused M5-M8 pins for us PixFalcon users ; add a CLI command adv-param to switch these PWM to those Aux maps for Quad. So far don’t know anybody using it for Hex or Octa - Being so small it’s commonly installed in tiny 250mm Quads but we still wish to have mission function outcomes to leverage the PX4 capabilities inside :slight_smile: - thanks!

I agree that being able to selectively map motor outputs and aux outputs to the available ‘motor’ outs would be very useful for driving a gimbal and other ancillaries.

Dear Mr. Lorenz,

I understood that PixFalcon does not have the AUX to trigger a camera.

Can it be patched to achieve so or alternatively use the PicoSwitch Relay ( when using it on an Octacopter?

Thanks and regards


Is this still an active topic? I have not been able to find any suggestions or working solutions for mapping the camera trigger signal to a main pwm port. If this has been solved or is in the process, please point me in the right direction :slight_smile:

Best Regards
Johannes Friis

Did this go anywhere. I’m keen to do autocamera trigger as well

Hello! I found a solution to your issue which I recently acquired. Is quite simple actually. If you still have the problem I can help you on making any camera function with pixfalcon.


Would you be kind and explain how you went about triggering the camera with a pixfalcon?

I’m only using the Pixfalcon as a camera trigger and a data collector for the logs so for my case, i have all 8 main-out ports available, but no AUX

Hi Agdroner.
I would certainly be very interested. Please let us hear more.
Best regards
Jakob Thrane

Sure thing!
We are using two cameras:

  1. MAPIR: you just have to make a ground connection to RC channel 7 and activate the trigger function (rc7_function), set your values and there you go.
  2. Canon with CHDK: You will need a switch for a 5V output. You can that the 5V input from the PM cable directly to feed the electronic switch. Also ground the RC channel 7, set values and plug everything.
  3. Hardware Modified Camera: use an electronic switch (I haven’t done this but a friend did it with success).

You just need the signal from RC channel 7 (or any channel) to tell the trigger to do its job. You used this electronic switch.

Hope this helps on your projects.

Thanks Agdroner.
But are you actually running PX4 software on your Pixfalcon? I Cannot find the “rc7_function” in PX4, its only present in ardupilot.

Hi Guys, do you have any news about this topic? there is a way to control the gimbal also with the free output?

Hi guys, I’m also in the same problem, have a ready flying wing with a camera activated by PWM, but no AUX. Please can someone write a code which allow to set the trigger on a MAIN output?

Me too, why is this not possible?

I hope this thread is still active. As I was trying to use camera trigger via MAVlink message but it seems that Telemetry1 (only one available on pixfalcon) did not give out the message. I can intercept all other message though. So my question is: does camera trigger message only send out on Telemetry2?

If the camera tigger message were broadcast to all telemetry channels, I can then make a small microcontroller to intercept this message and make a trigger signal.